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Hi all:
I found this Forum while looking for a tire diameter chart of all things and thought you might be able to answer a couple of questions for me.
I have a 1954 GMC 350 ser. (2 Ton) flatbed about 8,000 lbs empty;a friend is working a trade for a '91 12V Cummins and NV4500 which I want to install in my truck. I'm currently driving it,but the swapped-in 302 gas six is REALLY tired-it will just barely carry both Overdrives empty,and with even 1000 pounds on it,both boxes are in Direct or lower. (Clark 5 speed w/.84 overdrive,Brown-Lipe 3 speed aux. w/.74 overdrive,stock 2 speed rear with 6.40 top side.) I think this Cummins engine and the NV4500 will be a good set up. I'll be selling the Clark,but will keep the Brownie intact. So far,though,nobody has any ideas for fuel mileage. I'm getting about 8-10 mpg now,and that's if I drive with the Clark in 4th (Direct) and the Brownie in 3rd (Over). If it'll carry 18 mpg empty and go 65 I'll be good with that;I can live with 10-12 loaded (figure a car trailer with a car on it,average load) but more would be better.
Anyone got some ideas? I read about the best rpm for mileage. According to my number cruncher I'd be doing about 2,000 r's at 60 mph-not as good as I'd hoped. 2500 rpm would give me about 74 mph;I could dial it down a bit to increase the mpg's. Thanks in advance for your input.
Speed
BTW-I live in Elko,and go to Reno fairly often.

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Welcome to the forums, Speed! I'm enthused about your project. My first job as a professional mechanic was responsibility for a fleet of 22 light and medium duty trucks, primarily 1949-60 GMC, Chevrolet, Ford and I-H. One of my favorites was the 1949 GMC 350 with a 270 that I rebuilt. I know your truck, current powertrain and chassis well, including the "Brownie" and industrial strength Clark 5-speed. What an era, the Advance Design cab, too! The 270 and 302 were the pinnacle of power and reliability for inline, four-main bearing sixes in trucks. Until the mid-'fifties Chevrolet's dip-and-splash engines could not hold a candle, Ford was nowhere until the Y-block V-8 era; however, I-H had the quality BD and RD engines that made a mark. That period was notable, over the years I have picked up a bookcase shelf of shop manuals covering the era. Need facts? I have them...

Your plan is reasonable, though there is a weight gain with the 12-valve Cummins. Being an inline, it should fit the chassis. The steering and front spring rate will have to be tested. You could likely benefit from either linkage type power steering or a later retrofit integral power steering box. Cooling will definitely need attention, the Cummins' BTUs may overwhelm the stock size radiator, though it's a big flow unit.

As for fuel efficiency, it's all about rpm with the Cummins. If you can cruise at 1600-1900 rpm with your overdrive and tire diameter, I believe that 18 mpg is readily achievable. My '05 Ram 24-valve HO was good for a consist 22-24 mpg with a stock curb weight of 7,800 pounds and driving within this sweet spot rpm. For mileage, the closer to 1600-1700 the better with the HO engine. Do the math on your tire diameter (revolutions per mile) and the gearing in overdrive. You should easily be able to pull the overdrive when running empty—maybe even loaded on flat ground.

Loaded fuel efficiency is a wild card. Your weak point is the lack of aerodynamics compared to more modern trucks. (The good looking Advance Design cab is worth it!) I'd still expect 16 mpg or better with the 1,000 pound load. What would kill the mileage is the anticipated 2000-2500 rpm engine speeds at cruise. This engine will boost and flow fuel to achieve this speed, and mileage would likely be in the 16 mpg empty and 12-13 loaded. I know from trailering and empty that each engine revolution over 1900 brings with it a noticeable drop in fuel mileage.

If you can re-gear or change tire diameter for 1900 rpm at 69-70 mph, the mileage gain would be dramatic...This fuel consumption thing is not about power, it's about engine speed. The engine's torque rise is quick, and the torque peak (plus the next 300 rpm or so) is the point for efficiency and mileage gains. Horsepower becomes a moot point with a diesel truck engine. In my view, the peak horsepower rpm figure (approximately 2900 rpm with the Hypertech tuning) for the ISB Cummins engine is more like a redline indicator. I can count on one hand the number of times my engine has been run to the horsepower peak rpm. In 140K miles since new, it's seen its 3400 rpm redline twice due to passing situations that I should have avoided. Frankly, the power is unimpressive beyond 3000 rpm. I see 2400-2600 rpm as the ceiling—period. In reality, I generally upshift to stay in the 1800-2400 rpm range to make usable power (torque plus horsepower) under load. I'm always conscious of engine loads and fuel efficiency.

Note: Here is a link to the tuning of my 24-valve Cummins with the Hypertech Max Energy software: http://www.4wdmechanix.com/Hypertech-Max-Energy-Power-Programmers-for-Jeep-4.0L-and-Dodge-Cummins.html. I'm not sure whether the tune improved or damaged mileage, there were many modifications to the truck at the same time...A friend has a stock HO Cummins truck like mine and has never seen beyond 18 mpg empty. He insists on upshifting at 2400 rpm. A new forum member in the Cummins fuel efficiency topic upshifts his six-speed manual transmission between 1100 and 1200 rpm when the truck is running empty, which I do as well with the automatic 48RE transmission. This is the "just get rolling from a stop" routine that diesel truckers apply. The NV4500 (rugged, I like it and have used it as a swap transmission) could easily be good for 1200-1300 rpm upshifts in your swap project. Under load, perhaps a bit higher. Here's where we gain overall fuel mileage.

Incidentally, my current 4.56 gearing (plus 0.69 overdrive) with 34.6" diameter tires is for trailering and a hypothetical 55-65 mph cruise with a 7500-8500 pound trailer in tow. 69 mph is the outer limits for acceptable fuel efficiency. (Of course, the Cummins 5.9L would be happy to make more speed and eat more fuel at the same time.) I expect distinctly higher fuel costs for speeds beyond 69 mph.

Please keep us posted on this project. Photos of the engine swap would be terrific! I'm looking forward to continuing this conversation...

Moses

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I understand about getting milerage-my current mileage in the GMC seems to run about twice the 5 MPG the old timers tell me I should be seeing,and my '81 Toyota 4X4 pick up,with its 300K engine,with compression so low I have to use Low Range to make it stay in my driveway,gets a consistent 20 MPG.

I'm running Bias 8.25-20's on the '54 now,as soon as I can afford to I'll be upgrading to 9.00R-20's and that's the size I was using on the number cruncher I use. ( http://www.rocky-road.com/calculator.html) I don't think I can go any bigger than that on these wheels,and it's the 5 lug front,10 lug rear set up,so I don't know if bigger wheels are available in my bolt pattern. At a 42 inch diameter and with a .85 High in the 4500,and a .74 High in the 5531 Brownie and 6.40 axle,1800 rpm looks like 55.891 MPH. I tend to short-shift when I can-that 302 just sounds too busy for my taste at anything over 2200 rpm,even though they say it's redlined at 3400 w/governor. I know this engine and transmission have a LOT of hard miles on 'em.

Am I right in figuring the 4500's High gear at .85? That seems to be "typical" for the overdrive ratio these days. I get a feeling I might have to find a single speed axle for this truck with a little longer legs than a 6.40. If I stick with a 2 speed with this lug pattern I'm solidly stuck with the 6.40 ratio. A 5.40 ratio would give me 66 MPH at 1800,if that ratio's even made. Okay,I just checked my GMC Assy.Manual,and they show an "HO72" axle that's a 5.14 ratio,and THAT would give me 69.6 MPH at 1800 RPM! All I have to do is FIND ONE.

BTW- I just picked up a pair of black leather bucket seats from a '90 Jeep Cherokee;a friend in Reno's giving me a pair of Astrovan pedestals,that SHOULD make 'em an easy install into the GMC. The stock seat's okay for short trips,but anything over 20 miles really puts the hurts on my back. The new seats will also make it possible for me to remove my cab gas tank and put some much needed storage where it lived. I've been running on a 40 gallon frame mounted tank,and know of a 30 gallon duplicate of it to install on the driver'side. (Just short enough to clear the Stack. )

I have some pictures of the truck as it is now,but don't plan to pull the truck apart for "Before/After" pics until I have the "new" engine/transmission in my possession.( A friend in Arizona is supposed to bring that engine and transmission,a PTO winch and a '48 Mack EG tractor to me,as soon as he gets his "ducks in a row",and take a 40 foot semi flatbed trailer and extra wheels and tires home with him.)

Speed

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Speed...I get a kick out of the older engine power ratings. Horsepower is always at some rod-stretching rpm for these long-stroke inline sixes with four main bearings. (Flathead Ford V-8s and Jeep L- and F-head fours had only three mains!) The only thing that saved these under-square engines was lack of compression. Driving pre- and postwar trucks is where you learn to appreciate peak torque—not horsepower. I had a '51 Ford F-3 with the last spur gear transmission and learned to shift up and down without depressing the clutch pedal. The clutch was for stops and initial starts. Double clutching was optional and the intended method of shifting.

Your 5.14 axle ratio idea would likely do very well. You still have the two overdrives. If you're bent on interstate speeds and the chassis is still taut enough, this is all workable. (Check the spring anchor and hanger hardware carefully, the kingpins, draglink and tie-rod ends, too. The steering gearbox is a rugged Saginaw recirculating ball-and-nut type and could still be functional, unlike a vintage Gemmer or Ross.) The new seats make sense, the factory bench is always broken down and in need of major help. When right, the OE seat is stiff as a board. The auxiliary fuel tank is a solution, keep the tanks well out of harm's way, including consideration for side impact.

The PTO winch is a novelty. Can you run it off the NV4500? There's a plate and access to PTO gears, is there actually a PTO drive available for the NV4500? If so, what is the use, wrecker winches?

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Old truck power ratings-135 hp i believe,for my 302;currently probably around 80.

I found out the 5.14 is a REALLY rare ratio. Everyone who puts a bigger engine in his (or her) truck wants 'em. That's what I'll need though. I'll do some searching......

I drove a '51 F-5 with that box as my DD for about 3 years,until I got my MG back together. I used to "half-double-clutch" the truck;that's when you'ready to shift,float it,pull it into neutral,then hit the clutch and blip the throttle to upshift,or pull it into neutral,jazz the throttle and hit the clutch and shift into the next gear down. Actually works pretty good. (blip and jazz-because it's easier to catch your gear on the way DOWN the rpm scale,going either direction)

Regarding the driveability of the GMC,it's actually in pretty good shape;I went through it last Summer and checked the suspension,kingpins,brakes (I changed it over to a dual reservoir M/C from a Chevy one ton van-same diameter bore,feels just like having power brakes.) Scrapped the HydraVac and original M/C,added an aftermarket adjustable proportioning valve inside the Right frame rail. (It still needs a little more front brake.) All the steering gear feels good,and it's due for another lube job sometime this Summer. Power Steering would be nice,but isn't essential.

This seat is original/"improved". The springs are all good,but it's so soft with padding it about folds me in half driving down the road.

Those gas tanks are built beefy enough they'll easily total just about any of these "modern" cars that decides to tangle with 'em. The Right tank is under the bed on the frame rail,just behind the cab;the Left one will be in the same location with the rear ends at the same distance from the front of the bed,leaving just enough room for a 4" stack up front,with plenty of clearance. The tanks are identical in style and diameter,one is about a foot shorter.

I'm not sure about the drive for the 4500 for a winch-I know they're available,but how much $$ ? After thinking on it,I'll run it off the main box so I don't have to spin both transmissions,and I can use the parking brake on the Brownie to keep it from rolling away while winching. I tell you what-those PTO parts are America's best kept secrets. Even the Dealers can't tell me what fits what unless I buy it NEW from them. (They must have a "Winch Wizard" in the back shop who works his magic to set up a winch for a particular truck.) I have 4 PTO drives in the shop,not a CLUE what any of 'em fits. Well,one is an air shift,so I assume it fits a 13 speed I had up for sale,and one is off an SM-465.

I'd planned to build a crane with a base I could install in the stake pockets,and mount the winch under the bed with a pulley on the bottom of the headache rack to direct the cable either across the deck or up to the boom. Now,if this Mack comes in,and if it'll run,I've decided on an old school tow bed for IT. The PTO winch would work on that,either as a primary winch or a recovery winch. It has 1/2" cable on it,so I'm guessing it'd be rated at around 15,000 pounds or so on a single line pull. Actually,my first thought was to just flat bed it,but it already has the whole air system for pulling semi trailers,and that'd be useful on a tow truck too.

Speed

12-27-15

Update-I now have a 5th wheel RV trailer to make into a 32 foot Car hauler. (The plan includes adding an axle,since it only has two,with 5 on 4-1/4 hub pattern 15 inch wheels.) Once I get my '76 Chevy's heads replaced and get a pair of front tires for it,I think I'll go ahead and pull the flatbed off the big GMC and install the 5th wheel plate,and it'll be the 2 car hauler. (Maybe 3 if I can ramp one up on the tongue.) Come warmer weather I'll drag the trailer to town and get it stripped down to a frame (Hope the price of scrap is up again,that'll help me with parts/supplies to get this done.) and suspension,get the third axle in,get the brakes re-wired and get the lighting done. With the third axle at the rear,I could add a 5 foot dovetail,making it about 36 feet of space,and some room on the tongue for either crates,parts or one end of a car or trailer if I make a ramp for it.

JS

Edited December 28, 2015 by SpeedCorrection/addition of information.

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Speed...The spur gear could be shifted without gear clash, using a variety of creative techniques. The key was engine speed synchronized to gear speed, with straight-cut gears and no synchros the challenge. These transmissions were rugged and held up well if you shifted them properly. Fully double clutching or sliding to neutral and matching engine to gear speed with the throttle were not alien concepts in the pre- and postwar era, though this four-speed gave way to a compound low and synchromesh (2nd,3rd and 4th gears) T-98 in 1952. Spur gears simply could not compete with GM's SM420. Ford did not have synchromesh in any transmission before 1939. During high school years, I had a '38 Ford half-ton with straight-cut gears and no synchromesh. No hydraulic brakes, either.

The GMC steering gear ratio is slow, these gears are very smooth thanks to the patented Saginaw recirculating ball-and-nut design pioneered by GM. I have rebuilt many Gemmer and Ross boxes, few GM with ball and nut. GM with worm and sector are another story, be very pleased that your truck does not have a worm and sector, worm and roller or cam and lever steering gear!

Tanks sound well in hand...You'll like the capacity. 110 gallons will easily get me from east of Reno/Sparks, NV to Moab, UT and back with a good margin of fuel to spare when running empty. (Estimating approximately 8900 pounds curb weight with full tank of fuel, I need to weigh the truck and confirm.) This allows for selective (I.e., less costly per gallon) fuel stops when trailering, too. I-80 at Wells, NV or Elko, Salt Lake Area, Green River even Moab are better fuel stops than in between. On Highway 50 heading home, I avoid fuel anywhere but Ely and Fallon.

Curious what you wind up doing about the winch PTO. The Brownie will certainly work if you have or can find a drive...

I like your Mack ideas, creative and practical if the older technology powertrain and chassis will meet your needs. The boom and deck could make a commercial tow truck or a museum/parade piece. You would have plenty of power if not in a hurry. This is unique, vintage technology with a stunning profile! Wow...go for it!

Moses

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That's one thing I love about the OLD Mack Trucks-they're usually nowhere close to fast,but they'll pull the top off a Mountain if you can find the traction and something to hook the chain to. I haven't checked the Mack for a PTO drive,it's about 600 miles away,but it probably has one. It has an OHV 354 C.I. six (Made by REO) and that 5 speed with a vacuum(?) shifted integral aux. box-Mono-Shift,I think.(Sitting here thinking of a way to shift it electrically without causing gear damage,so I can run it like a 2 speed axle. An old school Mack driver I know said he'd seen 'em shifted via cable,vacuum and even hydraulic,but never electric. Apparently,since it has to be "floated" into gear,the shift either has to be carefully timed or the mechanism needs to be able to shift kinda gently. I have an idea,but I'll need the transmission before I can check it out.) I can only guess at gearing (The Mono-Shift is a Direct High Gear,with an Underdrive),so I'll be surprised if it'll go more than 35-40 down the highway. It has 10.00-20's on it. It HAD a 5th wheel,but the guy who has the truck sold the plate;I still have the one off my '45 EH,so that's an easy fix if I want to use it.

My biggest concern on the Mack is brakes-in the 14 years I owned the '45 EH,it had actual brakes for about 50 miles,on the way from Reno back to Elko,towing my '62 Chevy one ton duallie,and that was after spending $200.00 for a new Master cylinder. The rest was just planning my moves carefully,driving slower and using the parking brake when needed. (I only used it on dirt roads,and streets as needed to get to the job locally,to move trailers and mobile homes,push cars,drag rakes etc. Rarely over 5 mph)

I figure the tanks I have in mind for the GMC should give me at least 900-1,000 miles range,worst case. At today's price,I'd be looking at around $230.00 to fill it from empty.

I've always liked the SM420-especially the LOW first and reverse. When my Brother and I built my '74 Chevy one Ton,I had the option to choose which transmission I wanted;we had my SM420,an SM435 and an SM465. I chose the 435,but regretted the choice later. I SHOULD have kept the 420 even though the 3rd gear synchro was shot.

I actually like the steering in the '54;it appears to need the toe-in set,the front tires appear to be scuffing a little,but it's not bad. I have a hydraulic ram for a power steering set up from a '73 Chevy C-60,but the pump had a broken shaft. (I bought the steering box to replace the manual steering box on a 66 Chevy C-60,and the seller said I could have everything related to the steering,so I went for it. The truck drove so nice with that box I never bothered with the power steering. (It was a bolt-on swap but I had to re-clock the steering arm about half a dozen teeth on the splines to get it centered.)

As for the tow truck idea,it'd be handy for me because I seem to be given a lot of vehicles missing wheels,suspension parts and axles. I could just skid 'em onto my car trailer,but they rip up the deck on it,and they don't slide off easily at all when I reach the landing spot. If I build a removable actual hoist,I could ise it for loading a truck,swapping out engines,dismantling old Mobile homes,etc. My favorite idea is still to build an Old Style tow truck with the Mack-I can see it in my mind,and it's gonna be so cool!

Oh-I wanted to ask,what do you think of that New Venture six speed? Is it as strong as the 5 speed? Does the 6th gear have a taller ratio than 5th in the 5 speed? Worth searching for?

Speed

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That electric shift might follow the approach with modern transfer cases. Look into the electrical engagement mechanisms on these late units like my Dodge Ram's NV273D. Worth a look, may provide some ideas...

The NV5600 is a sturdy unit overall, though there have been synchronizer problems, the parts availability for the unit is not good, either. You'll find ratios at this link for the Dodge Ram version. Author does mention synchro troubles under load. We have a friend whose Ram/Cummins and trailering wore out (overwhelmed?) the synchros in his NV5600. It's a busier unit for rebuilding, too, though I would like the challenge! Note the torque specs, the HD upgrade was apparently not in the cards for Dodge/Ram: http://www.dieselhub.com/trans/NV5600.html.

Moses

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I'll see if the Dodge dealer here will let me look at their info on adjusting the T/C shifters on the late models. (There will be pictures...) That's gonna be a later on kinda project,good idea though. I'll ALSO see if there's any retro-upgrades for the 5600. It appears to be substantially beefier than the 4500,judging from the difference in weight,torque rating and I like the gearing better. (It's almost MADE to be linked to a Brownie.) It sounds like the synchronizers are also functioning as thrust washers,from the reference to troubles "under load". Do you know if there's a place to install a debris filter on these transmissions?(assuming they have some sort of oil pump to lubricate the input and output bearings) I'm not too worried about the synchronizers as long as I don't have to worry about chunks circulating through the gears and bearings,but apparently,breaking a synchro ring creates a bunch of end play,eventually leading to a "put on your walking shoes" catastrophic failure. If you're set up for it,maybe there's a market to do rebuilt and upgraded 5600's. I don't know if I'd be able to afford a 6 speed of any condition,but right now I figure that's a better possibility than I have of finding that 5.14 axle. I'm thinking the delivery trucks (UPS Van styles) of the 50's/60's would be most likely,as owners of those were more concerned with the cost of operation,so they'd more willingly order the taller gearing. I may have to advertise for that axle or gear set. BTW-How are you at setting up a ring-n-pinion? I haven't had much success with it.

Speed

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Speed...Looked at the parts schematic, no pump, filter or any other creative lubrication methods, just a typical manual transmission that relies on slinging oil upward from the spinning counter gear, the time honored approach. Would be very busy inside the case and likely not a candidate for an internal filtration system. However, here's an idea: Advance Adapters has used an external oil balance tube on the Atlas transfer case. They ran a transparent oil resistant plastic tube from the drain plug hole to the fill plug hole to keep oil somewhat level and allow filling to a specific point. Perhaps that triggers some thoughts.

You might devise an external pump (electric) and filtration system that uses these two plug points for access and return. Weight of the oil would be a factor for circulating oil efficiently. There would be a need to assure the proper level of oil in the transmission at all times. No cavitation would be essential. There are hydraulic pumps and filtration systems that can accomplish this. Overfilling must be avoided, too much lube would blow the front bearing retainer and other seals out of the transmission. Available oil would be a specific amount that assures safe oil level in the transmission at all times. The pump could be operated periodically if more practical, like when the oil is warm/hot to aid circulation. A spin-on filter compatible with the oil viscosity would work well here. Here's a quick view of some filtration options from the Summit Racing catalog, you would need an inline pump:

Rebuilding the NV5600 would not be a problem, parts sourcing would. Likely, if enough volume existed, a machine shop (U.S. preferably) could produce improved synchros. Most suppliers go to Taiwan for this kind of manufacturing, the metallurgy is better than China proper. It could be done.

I've always been academic with mechanics. As a light and medium duty truck fleet mechanic in the late 'sixties and early 'seventies, I worked on everything and anything that came up. I have accumulated four bookcases with shop manuals and service related information. I don't hesitate to work on anything that has a companion shop manual. Axles are among the work I do, automatic and manual transmissions and steering gears, too. We ran a restoration shop for vintage and muscle era engines, transmissions, axles and steering gears for several years. My library coverage dates back to 1925 with automotive and trucks, Harley-Davidson from 1917-98. Ring-and-pinion work is not as daunting when you follow a factory workshop manual or traditional professional series guidebook. I always do.

You might find a late Cummins ISB version of the NV5600, though it won't be cheap if in good condition. You're a real truck driver and could keep the synchros alive by driving sensibly. I like your 5.14 idea, it's less costly. Bread trucks and delivery trucks? Don't give up on that idea.

Moses

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What do these transmissions use for lube-90 wt. or ATF? On the T/C in my Bronco II it calls for ATF,but I changed it over to a 10Wt. synthetic motor oil. It's been working like a champ for 4 years now,and that includes highway trips,Four Wheeling and two scrap runs of about 15 miles one way towing a car trailer with over 9,000 pounds of metal (Hell of a load for a 2.8 Liter to have to pull!),and it even gained me a couple of miles per gallon in the deal.

I may have to put the 5600 and the 5.14 axle idea on a back burner while I get other stuff done,and while I wait for "the deal I can't pass up". Looking at the details in my Assembly Manual,I was mistaken on the 5.14 ratio-it's for a ONE ton. The BEST factory option for the 2 Ton axle is an H-150,with a 6.17 gearset,better but not nearly better enough. The actual rear axle I have is an Eaton 1350,but I don't know if a single speed carrier will fit the housing,since I have the 2 speed. If it WILL,I still have to find a single speed 2 Ton rear end,THEN try to find the gear set I need. I'm pretty sure they used the 5 lug/10 lug wheels well into the 70's,so maybe I can find a complete rear that could be installed on my springs. I ran across an abandoned truck,about a '70 or '71 Chevy C-60 last Summer that had the same set up,wheel-wise,as mine and a single speed punkin,but it was gone when I went back to get it about a week later. I think that's what I'll have to do.

I'd intended to hire a friend of a friend to do my conversion,since he does a couple per week,and knows all about the conversions,but everything I'm reading tells me that except for a little fabrication work it's a pretty easy swap,so I'll probably do as much of it myself as I can,and call in the experts if I get in a bind,or for special stuff,like the drive lines. (I'll need to damn near start over on those-my rear one,from the axle to the output of the Brownie needs to be re-tubed 3 inches longer to get rid of a vibration in the slip yoke,and the one from the Brownie to the transmission will need to be shortened and a new front yoke to fit the 4500.) Not sure about cost-just these changes will be around $250.00. I'm going to find out about changing all four yokes and switching to a more common u-joint type,which essentially would be starting from scratch. (Made that much easier if I find a later rear axle to install.) I think that'd smooth the drive train up a bunch,too.

Something else I was thinking about is an intercooler. Would that be worth doing? What external measurements would I be looking at? Would there be a problem with mounting it under/behind the front bumper,angled back at the bottom (---O----------O/ < only more so) for ground clearance,with ducting and a couple of electric fans to keep air flowing on low speed hard pulls. I was also thinking about building an air dam under the bumper from thick conveyor belt about a foot wide,to maybe help the truck bash through the air.

Speed

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Speed...Valvoline has the best oil application chart online. I downloaded a PDF that's at these forums in a reply. I use these recommendations, Redline is another source if you can afford the price of admission...

Sounds like you hit the wall with the axle ratios unless you swap out the entire rear axle for a later model application that might fit. Two-speed could reduce the available applications. The NV5600 or an NV4500 are at least a Dodge Ram offering for mate-up to the Cummins. Drivelines are always a part of these swaps.

Intercoolers provide definite gains, though any kind of boost in diesel power has its downside. I'd try stock first and see whether that's the power you want. The intercooling makes a denser charge, advantageous but also a boost in heat. A pyrometer is in my towing future, should be yours too if you have access to one.

As for aerodynamics, the Advance Design is not a real candidate. They look fantastic, though! An air dam might have minimal benefit.

Moses

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Regarding axle ratio,I'm pretty sure I can fit a later,same sized single speed under the truck;the critican concern,for me,is spring width at the spring pads. It's hard for me to imagine the spring spacing changing enough to be a problem. Within limits,I can make some offset centering plates to line up the center bolts,and just set the U bolts a little farther apart to compensate for the change. Brake lines are no problem,wheel lug pattern is "easy"-they only had a couple or three different hub styles avaailable for the 1-1/2 and 2 tonners. A late 60's or early 70's truck would very likely have gearing suitable to run at 60-65 mph with a Direct 4th or 5th gear,especially with an engine bigger than a six or a smaller smallblock. I expect the brakes would be better,seals and bearings would be easily available,and a suitable yoke to upgrade to a better u-joint would be easier for the driveline shop to find. AND a later truck MIGHT have brackets I can use to put some SHOCKS on my truck! I'll have to look and see what kinda year-spread I can use,get some measurements,etc.

I guess I was figuring the intercooler might give a little "free" horsepower,so I could get away with less throttle. You're right though,better to leave things as stock as possible-less to give problems later on.

On my list of "to do's" is re-gauging my truck;I'm getting a couple of extra dash panels,and re-fitting them with more modern gauges,including a Tach and a Pyrometer,and the gauges are whether I change to Diesel or not. I'm so tired of not being able to see the meters at night-it'd be wonderful to have internally lit gauges,maybe with LED's. The ones I have work okay,but the lighting on that model truly sucks,and once they start getting all faded and discolored they're even hard to see in daylight.

Speed

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The later axle does make sense in a variety of ways...Lamps are vintage and were dim when new. Classy looking but not practical. You might look at the classic/street truck aftermarket offerings, Advance Design trucks are popular, and there are LED lamp replacement dash inserts that might keep the original shapes and cues but actually offer luminance.

Shocks would be nice. The springs rates were so high and speed limits so low that shocks were non-essential. This is a very interesting and fun project...

Moses

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I think this truck will be as fun to build as it'll be to drive,and I LOVE to drive it already. The only factor that keeps it parked is the cost of operation. Hey-I just ran across this set up;I had considered something like it for the 302. What do you think? They say they even work on Diesels. http://globalenergydevices.com/dry-duo I'm curious what kind of "power increase" they're talking about. As is typical in my life,the fun is only limited by what I can afford to spend on it. Much of what I do seems to be "Redneck" natured because of the expense. Part of the fun,though is finding a way to make things work when you can't come up with the "right stuff". (It's interesting to see how some people think if you can't buy a part to make something work,it just can't be done. That just makes me think,"What could I modify to make it do that?" That's actually like my Signature on another Forum;"HMmm-What could I make outta that?"

I think I can make LED's work on about 99% of the truck and have it still look "original". I ALWAYS convert to sealed beam Halogen headlights. My GMC's amber fog lights are also Halogen sealed beams. I tried LED 1157's (two different designs) for the tail lights,but just couldn't get them bright enough to make me happy,so I'll probably go with the rubber grommet mounted LED's like the OTR rigs use,as well as the side markers,and Harbor Freight sells a rubber cased Halogen work light with a swivel mount that works awesome as a back up light.(TWO of 'em) (I'll be "light poor" before I'm done-I have the GMC,a car trailer,my '66 Pontiac Catalina,probably the '48 Mack EG and eventually a '53 Chevy 1-1/2 Ton dump truck I'll have to do. (The dump truck will get the GMC's 302,rebuilt,and possibly the Clark 5 speed when I switch to the Cummins.)

If I can work up the brackets for tube shocks on the rear (I'm thinking something like quad Rancho 5000's),I have an OEM set of lever action front shocks off a '49 Mack School Bus I think I can make work. (Or,more of the afore-mentioned Quad Ranch 5000's).

Naturally,there are a LOT of things that just take cubic MONEY-no substitutions possible. Shocks,the change to Radials,the lighting upgrades,etc. ,but I'm always running across cars,trucks,other stuff people give to me to get it out of their way (or USUALLY to get it out of their WIVES' way) that I can sell or trade for stuff I need. And MOST of it doesn't have to be done right away,so I can piece it together,or save up for it,or not do it at all and just dream of getting it done eventually. I really enjoy creating a plan for what parts I'll use,how I'll make things work,even what they'll cost. I'm a "Listoholic";I make lists of everything,what I need to get done on a particular day for instance. If it isn't on the list,I'll probably forget all about it.

Once I get started on the Cummins Conversion,you're always welcome to come up and get your hands dirty and enjoy a cup of coffee. Well,you can come up anytime for coffee.

Speed

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Speed...I tried a homebrewed recipe for a hydrogen gas supplement on the 4.0L Cherokee several years ago. It used baking soda and an electric element in a glass jar, very primitive and, frankly, it proved useless. This "kit" seems more sophisticated and may actually work. The concept appeals to me, though we all know where "concepts" often lead. I'd like to read testimonials and documented tests.

Motorheads have a penchant for "projects" and planned doings. I have my share, too. The coffee break sounds tangible and appealing!

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This Mack's engine ran great considering it had an updraft carb I couldn't even remove. (My hands just don't articulate that way.) It has a 5 speed with a Direct 5th,and 6031 Brownie and single speed axle with 6.86 gears. I was especially proud of the fact that,with absolute garbage for wiring when I bought it,(I touched the headlight wiring and all the insulation crumbled and fell off.)we finished up with EVERYTHING working (even the little marker lights on the headlights!) and a 140 amp Leese Neville one-wire alternator. (The wipers never worked,but THEY weren't electric-they were vacuum.) We used a wiring harness from a '75 Chevy pick up,as well as the fusebox, switches and relays from it. I was able to use the stock "Mack" knobs for the switches and the cigar lighter. I ended up selling the Mack to a local Propane Distributor who had one like it as their very first truck when they opened in 1954. I should ride to Wells sometime this Summer and see how (or IF) the restoration of the Mack is going.

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The Mack lends itself to restoration. The new owner should be motivated, this is an intact truck...with interesting gear works, too!

Thought I recognized the fuse box. We had '70s and '80s GM trucks. Our '73 K10 4x4 was a winner with 350 V-8, SM465, NP205 and 12-bolt Saginaw rear axle. A favorite! The two Suburbans were each 3/4-ton 4WDs, an '86 and an '87 both 350s, '86 carbureted, the '87 had TBI, THM400s and Corporate 14-bolt rear axles. GM built great trucks in that era, a real rival was I-H through '75. Ford's F250 High Boy 4x4 got the job done, too. An F350 4x4 by 1979 was even better.

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All about gearing, Speed! A vintage CJ from the Kaiser Era with a T-98A transmission could climb a tree in low range, compound low gear of the transmission. The 12V starter motor could crank and start the engine on a steep gradient in gear with the clutch engaged. I'm sure the 6V starter in your GMC could do this too with the gearing you describe, at least on level ground!

That's how these vintage engines survived. A realistic highway speed for that truck was likely 45-50 mph with any kind of load...on flat ground.

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Yeah,I think it'd run 50 with both boxes in Direct,even loaded and with the 90 meager horsepower it probably has now.

I've driven this truck half a block on the starter to get it out of the traffic when I ran it out of gas. I've also used the starter to nudge it just a little when using the clutch might be too much.

Hey-I'm planning to get my rear driveline section replaced as soon as I can swing it;It's built an inch or so too short,and is getting a wobble at the slip yoke from not having enough spline engagement. I want to upgrade it to more common u-joints and replace the slip yoke with a new,and longer splined one,and go with a little beefier tube. I figure,with TWO overdrives and the 6.40 axle I'll be running for the next little while,that driveline will be spinning pretty fast,so I want it to have every advantage I can give it. The driveline shop here said they'd re-tube it an inch longer and install near new u-joints for $250.00,but if I can afford it,I'd rather start fresh and go with a little overkill. What components would you use? Fine spline or coarse? What size u-joints? I know they'll have to have grease fittings. What's common,but suitable for what I'll be doing? I'm told they do an excellent balance,and that's gonna have to be MANDATORY with me,regardless of what else they do. I'm not going to try to make the whole drivetrain perfect (I'm sure both boxes have loose bearings,etc. that won't be helpful,and ALL the u-joints could probably stand replacing-LOTS of expense there. THEY might get upgraded next.),but I'll work from the back forward,since that's the problem I KNOW needs to be fixed;a small problem at the nose will often magnify as it goes back,to become a BIG problem at the tail.

I decided to change out the taillights on the GMC;I have a pair of taillights from a '66 Pontiac I'm mounting just below the deck on each side. I can use the ones I have on the truck now,from a '70 Chevy stepside pick up,on the utility trailer I'm building from a '32 Ford rear axle and a '40 Ford pick up bed,solid mounted,no springs,hitch welded to the end of the torque tube. the fenders were toast so I'll use a couple of little "cycle fenders" off an old wooden trailer that self destructed hauling a Harley in from Ryndon.

Speed

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Hi, Speed! First off, before spending money on these drivelines, are you committed to the current gear train and engine location? If you do a Cummins swap with an NV4500 or any other creative magic, you'll need to resize the driveshafts. When you're considering the current upgrades, the length of these shafts needs to be "permanent".

Guessing that you're restoring the GMC and keeping the gearboxes and engine position, the best build of a driveshaft is heavy-duty joints and couplers. The more splines, theoretically, the stronger. All of this is relative to the engine and torque applied. 90-110 horsepower would be easy on just about any spline arrangement. For the Cummins, increased spline count would be desirable.

U-joints should be quality, I like Spicer, Detroit or Delco for OEM replacement, NEAPCO and others produce decent products, too. You do want "heavy-duty", often the HD is a permanently sealed joint without a drilling for the grease fittings. Front live axles required sealed joints at the steering knuckle joint of the axle shafts for that reason. If you want grease fittings like the OE, make sure the joint is rated well for your GMC application...

Very important to driveshaft life is the driveline and U-joint angles. Your truck is relatively stock and certainly does not have a "lift kit". I would still check the driveline/U-joints angles.

Moses

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I'm planning to stick with the Brownie,and the axle I use will have to be the Eaton 1350 2 speed until I can find a later single speed that can use the same lug pattern,at which time I might have to re-do the driveline AGAIN. For now,since that last link already needs work,I figure I'd rather do it up right than patch it up. That way,no matter WHAT,I can drive it and not worry about it. I'll do all my adjusting in the section between the Brownie and the 4500. So far,I've been hearing the bellhousing to block line can stay the same with the Cummins as with the engine I have. Therefore,unless I've been misled,the only actual change would be the shaft between the Brownie and the 4500. I don't have measurements to compare yet,as I'd intended to get everything else put together then measure and order the driveshaft. For u-joints,I like Spicer too,but the guy at the driveline shop says he's having trouble with price on 'em,so I think he's switched to NEAPCO. I'd prefer the grease fitting to the added strength of the HD option,since I don't anticipate doing anything that could break one. (Theoretically,an axle would twist off before I could break a u-joint.) As it sits now,the drive line angle is suspect between the end of the transmission and the axle yoke,the "adjustment" being the height of the Brownie. When Jess looked at the truck to find the vibration,he said it looked good as is,but without his angle tester he wasn't solid on that. If it turns out to need adjustment,I can raise or lower,or tip,the Brownie a little.

I just measured my tires and they're 38.5 inch diameter,so "Theoretically" my low,low,low speeds should be even lower,but they figure faster (or LESS slow). At 3400,it went from 3.82 to 3.96 MPH-How did THAT happen??

Speed

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All of your OEM U-joints were grease fitting type, I know from a good deal of personal experience! I serviced these period trucks from high school in the mid-'sixties onward, and as an equipment operator, "lubrication engineer" was part of the job!

Understood that you'll be reworking just the driveline with known, permanent length. The Brownie does sound like the practical U-joint angle adjustment point...I'd adjust U-joint angles before taking driveline length measurements.

What's the final low, low combined transmission, Brownie, two-speed axle reduction ratio? We can do the math on tire revolutions per mile and resulting MPH based on the gearing. Let's see where the error is...

Still excited about the Cummins engine swap...What's the weight difference between the Cummins engine/flywheel/clutch and your GMC engine/flywheel and clutch?

Moses

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I'm only guessing on the weight difference,but I'm going with something in the 300 pound range. The 302 is a pretty heavy engine,and the Clark isn't very light either. Even if I'm off a bit I don't think it'll be enough to be a problem. Jess is pretty good at his job,so I'm going to figure my DL angles are okay.

Now-for gearing,I went with:

38.5 inch tire diameter

6.06:1 Low Clark 264VO

2:1 Brownie 5531 Low

8.10:1Eaton 1350 Low

3,400 RPM

================

3.968 MPH

I see where I screw'dup-it was in my first total. I suspect I was guessing at the low range ratio in the axle,before I found a definite number. I think I was guessing it to be an 8.41 or something like that. THAT number figures out to the 3.82 MPH figure. Okay-I got it now. Here's the number cruncher I use. There's more stuff you can do with it.

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The calculators online are very helpful, I use them all the time. Have an old Wolverine camshaft selection software that offered even more info, unfortunately it's 3.5" disc and old DOS. Windows 7 eliminated backward compatibility to earlier DOS software. That terrific Wolverine program and its "utilities" functions became a relic...Glad there are online calculators!

You "did the math", Speed, the numbers sound good! Plenty of gear reduction...

Moses

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I woke from a dead sleep last night to realize a '66 Chevy 60 Series I "restored" 4 years ago has the exact axle I need. Don't know what gears it had but it was a Limited Slip,and with a 292 and 4 speed,it ran about 60-65 comfortably on the 50 mile delivery to its buyer's ranch. (I wonder if that truck's in the "back 40" yet....)

Speed

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There's an Advance Design long bed pickup in the neighborhood with a very straight and rust-free (Nevada?) sheet metal. Has the quarter window cab, very sharp profile. I stride past this truck on my early morning walk. I've considered the truck with a Cummins diesel or Duramax, and even a 292. The 292 is a pristine swap with a '55-'59 V-8 iron bellhousing, easily fab'd front mount and a direct bolt-up for the SM420. The longer chassis is an open driveline (no torque tube), which makes this even easier.

With just minutes to think about the truck, I have considered the practicality of tugging a travel trailer behind a vintage truck at interstate speeds. The biggest weakness would be the narrow, high-stack springs...Some would simply find a later 4x4 chassis (a K20/2500 would be likely) with beam axles. They'd swap over the body to the modern chassis.

Have you towed bigger trailers with any of this vintage light truck chassis stuff?

Moses

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The truck you're describing,if I'm not mistaken,is likely a one ton. They (the ones with a 9 foot bed) are quite collectible,so if you can snag it for a fair price,you should. If it was mine,I'd go with a 292,alternator,install electric wipers from Newport Engineering,swap in a 4.10 pumpkin from a late 60's 3/4 ton GM truck,swap the Master Cylinder over to a dual reservoir;if you find the right one at a parts store for a drum/drum system,it's just a matter of a mounting bracket and a couple of brake lines. If you use one set up for a disc brake front end,just pick up an adjustable proportioning valve from Summit,put it in the line to the front brakes and you can adjust the pressure to work as you like it. (I did this on my '54 two ton.) For SOME reason,getting the new M/C with the same bore diameter the truck has makes it feel like power brakes,but not as sudden. If the brakes aren't beefy enough,you can get the kit with a booster,but I don't think you'd need it.

Personally,I'd run it with the springs it has and see how it drives. (Maybe remover a couple of leaves if your trailer's not a 5th wheel or goose neck.) If you want different springs,it may be possible to find later,wider springs in a wrecking yard,and if you grab the shackles and frame brackets,it might not be too tough to just change the whole set up to the older truck. The problem I see with going to later axles,frame conversions,etc. is that the wheels will stick out too far. If you go with a cab & chassis,you might cover it by going to a 2 ton front group (longer hood,wider fenders,still fits the smaller truck cab),but it'd be a bit of work to make it all gell. If you do it,PLEASE don't change it over to hanging pedals-that just ruins the character of the truck.

After I ruined the second rear end on my '57,I used a rear end from a '74 Chevy 4X4,with my stock springs,the newer u-bolts and spring plates,and I made some shock mounts to use my old shocks. The '57 driveline bolted right up. It was MUCH easier than I was told it'd be. (wrong spring spacing,wrong spring width,wrong this,wrong that,etc. There USED to be an outfit that sold a roller bearing kingpin kit that was GREAT,but they're not around now.

Also,(and I'm not sure one is offered for a 3/4 ton) a tapered roller wheel bearing conversion seems to make these ol' trucks drive better on the highway. You MIGHT be able to work up a conversion if you're in good with someone at a bearing house.

(If it's a GMC,it's "oldGMCtrucks.com" .) Better yet,log in on both-Lots of good information and good people there.

They have a lot of information on conversions to disc brakes,etc. In the Gallery are some pics of some trucks I've owned.

I towed a 35 foot 5th wheel RV a lot with my '57 GMC pick up. Even being a half ton it did fine. (I shut down a Ford one ton with a similar sized trailer between Immigrant Summit and Battle Mountain,he backed out of it at about 80,I ran it up to about 90 before I let up.) ONE thing you'll want to do is get a pair of 16.5 wheels and 9.50-16.5 tires for towing. I noticed they make the truck rock-steady with a big trailer. Also,make damn sure your trailer brakes are working right. I'm not sure my trailer brakes EVER worked,and the pick up's brakes worked fine unloaded,but doing all the braking for a trailer that size gave them a working life of about 100 miles. When I brought the trailer from Elko to Reno I wasn't too worried when the brakes went bad,because I knew the road very well,but on the move from Reno to Boise,it was a different story. I discovered the brakes no longer did as I was pulling off 80 into Winnemucca. I didn't have the time or the money to go through the brakes so I just bashed on,regardless,with my ex,Dawn,leading the way in her '79 Mercury Zephyr,using her CB to tell me what was coming up-idiot drivers,steep grades,cattle,etc. I didn't know the trailer was as heavy as it was. On THAT trip I had to skip the 16.5's,as they were showing wire and I couldn't find used tires that size. I ran E rated 215-85R-16's on all four corners,and between Caldwell and Elko TWO of 'em started to blister;once I got to Elko another one threw tread. APPARENTLY,this size,even E rated,was too small for the load. After that,I started running 235/85R-16 E's,and never had another tire problem. I DID have to replace the 347 V-5 (3 dead cylinders) with a '68 Pontiac 400,and grenaded two rear ends,one towing the RV out to storage (Exploded the spider gear case,bent the pinion shaft,cracked the punkin.)and one just pulling away from a traffic light on my way home from work.(broke the ring gear in 5 pieces,none stayed secured. It was so weird-pulled away from the light,shifted to third at about 2500 rpm,let the clutch out and it just coasted to a stop,still idling in gear. Got out and looked under the truck,driveline still spinning smoothly.....

Speed

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The truck you're describing,if I'm not mistaken,is likely a one ton. They (the ones with a 9 foot bed) are quite collectible,so if you can snag it for a fair price,you should. If it was mine,I'd go with a 292,alternator,install electric wipers from Newport Engineering,swap in a 4.10 pumpkin from a late 60's 3/4 ton GM truck,swap the Master Cylinder over to a dual reservoir;if you find the right one at a parts store for a drum/drum system,it's just a matter of a mounting bracket and a couple of brake lines. If you use one set up for a disc brake front end,just pick up an adjustable proportioning valve from Summit,put it in the line to the front brakes and you can adjust the pressure to work as you like it. (I did this on my '54 two ton.) For SOME reason,getting the new M/C with the same bore diameter the truck has makes it feel like power brakes,but not as sudden. If the brakes aren't beefy enough,you can get the kit with a booster,but I don't think you'd need it.

You build a good case for this truck, I may take a closer look... I've done brake (dual-braking system) upgrades on a number of 4x4 projects, a smart safety option. Made a nice setup for the '55 CJ-5 through-the-floor pedal arrangement featured in my Jeep CJ Rebuilder's Manual: 1946-71.

Personally,I'd run it with the springs it has and see how it drives. (Maybe remover a couple of leaves if your trailer's not a 5th wheel or goose neck.) If you want different springs,it may be possible to find later,wider springs in a wrecking yard,and if you grab the shackles and frame brackets,it might not be too tough to just change the whole set up to the older truck. The problem I see with going to later axles,frame conversions,etc. is that the wheels will stick out too far. If you go with a cab & chassis,you might cover it by going to a 2 ton front group (longer hood,wider fenders,still fits the smaller truck cab),but it'd be a bit of work to make it all gell. If you do it,PLEASE don't change it over to hanging pedals-that just ruins the character of the truck.

Agree completely about the track width issue. These projects are always difficult to sort out. If I want a '67-'91 era GM beam axle 4x4 truck or a K-model Suburban/Blazer to restore, that's another story, I'd stick with the later body type. The 292 inline six is a great fit into a vintage Advance Design chassis, and it offers a 7-main bearing improvement.

After I ruined the second rear end on my '57,I used a rear end from a '74 Chevy 4X4,with my stock springs,the newer u-bolts and spring plates,and I made some shock mounts to use my old shocks. The '57 driveline bolted right up. It was MUCH easier than I was told it'd be. (wrong spring spacing,wrong spring width,wrong this,wrong that,etc. There USED to be an outfit that sold a roller bearing kingpin kit that was GREAT,but they're not around now.

Interesting that GMC used Spicer 44/45 axles when Chevy used the Corporate offerings. I had a '60 GMC pickup (SWB step side) with a 305 V-6 and Spicer 45 rear axle with limited slip. The limited slip diff was prone to ring gear bolt loosening...GMC maintained its own identity until the late 'sixties, these trucks stood above the Chevrolet offerings. With the disappearance of the 305 V-6 offering, GMC became a Chevrolet with a GMC badge. (I worked for a Chevy dealership at Coquille, Oregon years ago. We saw a spanking new '77 Chevrolet pickup come off the transport with a GMC steering wheel and GMC tailgate badging in place! They each came down the same assembly line, and apparently the parts got mixed.)

Also,(and I'm not sure one is offered for a 3/4 ton) a tapered roller wheel bearing conversion seems to make these ol' trucks drive better on the highway. You MIGHT be able to work up a conversion if you're in good with someone at a bearing house.

There have been part number conversions between ball and tapered roller wheel bearings. The "kits" were simply replacement bearings that happened to fit the I.D. and O.D. Tapered rollers are a distinct gain, though GM light trucks and cars survived the "New Departure" versus Timken patent for many years. Adjustment methods and wheel bearing lubricants are distinctly different between ball and tapered roller wheel bearings.

(If it's a GMC,it's "oldGMCtrucks.com" .) Better yet,log in on both-Lots of good information and good people there.

They have a lot of information on conversions to disc brakes,etc. In the Gallery are some pics of some trucks I've owned.

Disc front is a definite advantage. Rear disc is an option...In the case of vintage rear drum brakes, a four-wheel disc conversion would make sense.

I towed a 35 foot 5th wheel RV a lot with my '57 GMC pick up. Even being a half ton it did fine. (I shut down a Ford one ton with a similar sized trailer between Immigrant Summit and Battle Mountain,he backed out of it at about 80,I ran it up to about 90 before I let up.) ONE thing you'll want to do is get a pair of 16.5 wheels and 9.50-16.5 tires for towing. I noticed they make the truck rock-steady with a big trailer. Also,make damn sure your trailer brakes are working right. I'm not sure my trailer brakes EVER worked,and the pick up's brakes worked fine unloaded,but doing all the braking for a trailer that size gave them a working life of about 100 miles. When I brought the trailer from Elko to Reno I wasn't too worried when the brakes went bad,because I knew the road very well,but on the move from Reno to Boise,it was a different story. I discovered the brakes no longer did as I was pulling off 80 into Winnemucca. I didn't have the time or the money to go through the brakes so I just bashed on,regardless,with my ex,Dawn,leading the way in her '79 Mercury Zephyr,using her CB to tell me what was coming up-idiot drivers,steep grades,cattle,etc. I didn't know the trailer was as heavy as it was. On THAT trip I had to skip the 16.5's,as they were showing wire and I couldn't find used tires that size. I ran E rated 215-85R-16's on all four corners,and between Caldwell and Elko TWO of 'em started to blister;once I got to Elko another one threw tread. APPARENTLY,this size,even E rated,was too small for the load. After that,I started running 235/85R-16 E's,and never had another tire problem. I DID have to replace the 347 V-5 (3 dead cylinders) with a '68 Pontiac 400,and grenaded two rear ends,one towing the RV out to storage (Exploded the spider gear case,bent the pinion shaft,cracked the punkin.)and one just pulling away from a traffic light on my way home from work.(broke the ring gear in 5 pieces,none stayed secured. It was so weird-pulled away from the light,shifted to third at about 2500 rpm,let the clutch out and it just coasted to a stop,still idling in gear. Got out and looked under the truck,driveline still spinning smoothly.....

Visions of the 347 V-8 and other vintage equipment is vivid. I owned a '55 Ford F100 pickup for seven years and went through three engine iterations. I did the Ford Y-block approach (312 with ECZ heads) and two GM engine swaps. My first GM conversion was a '57 Pontiac passenger car 347 V-8, rated 270 horsepower and fully capable of producing it! (Did a mate-up to the Ford 9-bolt side cover 3-speed manual transmission and later played with a dual-coupling Hydramatic.) I was totally engrossed in Pontiac engines at the time and read Smokey Yunick's book on Pontiac V-8s backward and forward. The last engine change was a Chevy small-block V-8 build that was much cheaper to keep than the bulky Pontiac engines. Loosening the press-in rocker studs was far less likely on the Chevy engines! As a point of interest, GM also fiddled with the Oldsmobile V-8s in '50s medium duty trucks.

Speed

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Speed...Regarding tapered roller front wheel bearing conversion kits for vintage GM trucks, I do recall the narrow spacing for the outer OE ball bearing, so the conversion kit's "custom" tapered roller and race make sense. For the stock ball bearings on the truck fleet I maintained, the option was the "Micro Nut", a fine tooth locking nut arrangement available in the aftermarket that resolved the questionable factory specs, which varied between the OE shop manuals and added to the confusion.

Directly from the 1955-59 GMC truck factory shop manual for a 100 Series GMC truck: "rotate wheel and torque spindle nut to 45-65 ft.lbs. then back off nut 1/6 turn (optimal), or as slight as necessary beyond 1/6 turn of the spindle nut". 1958 Chevrolet truck factory shop manual neglects to mention backing off the nut and simple shares the torque spec of 45-65 ft. lbs. for 1/2-ton trucks, which I'm sure fried a lot of wheel bearings! Passenger cars and the older Advance Design light duty 1/2-ton trucks were 33 ft. lbs. then back off spindle nut to the first slot (approximately 1/12 to 1/6 turn range, which makes better sense and was a spec worth acknowledging for the lighter 1/2-ton trucks). Your big 350 GMC should have tapered roller front wheel bearings and a different adjustment spec than the light-duty trucks.

The big Caddy V-8s were terrific for reliability and massive torque. Lower compression smog era, they still produced great power and could run on unleaded regular!

When I played with Toyota FJ40 Land Cruisers, which ultimately led to writing the Toyota Truck & Land Cruiser Owner's Bible, Cadillac Motor Sports was a popular option to the common Chevy V-8 swaps. When owners wanted serious torque, they turned to these big displacement Caddy V-8s, the Turbo 400 was a natural, and a manual transmission conversion was possible. (A pilot bearing bore would be essential for that approach! See you local machine shop.) As for a 472 Cadillac engine in a Chevy pickup, this had to be a conversion. 454 or 396/400 (big block) maybe, not a Cadillac. If a Cadillac, the truck would be a museum piece or collectible.

Good luck with the dentist!

Moses

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"When I played with Toyota FJ40 Land Cruisers, which ultimately led to writing the Toyota Truck & Land Cruiser Owner's Bible, Cadillac Motor Sports was a popular option to the common Chevy V-8 swaps. When owners wanted serious torque, they turned to these big displacement Caddy V-8s, the Turbo 400 was a natural, and a manual transmission conversion was possible. (A pilot bearing bore would be essential for that approach! See you local machine shop.) As for a 472 Cadillac engine in a Chevy pickup, this had to be a conversion. 454 or 396/400 (big block) maybe, not a Cadillac. If a Cadillac, the truck would be a museum piece or collectible."

I'm wondering if a thin bellhousing spacer and a "bolt on" pilot bearing that attaches via the flywheel bolts and "cups" the end of the crank for alignment might be possible. Not having a Cadillac motor sitting in front of me,it's hard to tell what could be done. I just hate the idea of pulling the crank out of a good running engine to get one hole machined in it. I can see that becoming the start of a classic "Money Pit". ("Do I stop here? Put in new bearings? Maybe I should do the rings while I'm this far into it. Well,might as well get the valves done too;since it'll all be apart anyway,this'd be the time for a trick valve job,maybe a cam and lifters......")

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Speed, as they say, "Great minds..." You guessed it. I went to the Cad Company website. They offer a manual transmission pilot bearing solution. It's their own billet flywheel. Here's the statement:

Transmissions

Why spend hours cutting boiler plate and home-building a plate to bolt your Cad to the Chevy TH-400? You only need to give us a call, order the Transmission Adapter Kit, and have at it. Takes a few minutes to take it out of the box and bolt in on! Got a Power Glide? Got a TH-350? Noooo problem. Call us up and tell us you want the flex plate with the multi-pattern for TH-400, TH-350, Power glide and even the 700R-4. We can even setup one with other TC bolt patterns, such as Ford or Chrysler, on request (but then you're on your own for the tranny adapter). Wanna run a clutch setup, so you can torque test your 4-speed (or 5 or 6 speed…)? No problem again. Call Cad Company and order up a Steel Billet Flywheel and Oilite pilot bushing (featuring a 166-tooth ring gear, for a standard Caddy starter, and no custom machine work required to install the pilot bushing).

So if you can afford the flywheel, you get to keep the engine intact. Apparently, they have ingeniously incorporated an Oilite pilot bearing in the flywheel. Here's a link to the website: http://www.cad500parts.com/catalog/page5.htm

What intrigues me is the scope of interest that still exists in an engine that has not been produced since the mid-'seventies!

Moses

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Hey-the GOOD stuff lives forever. Look at the ol' 392 Hemi-the people who love 'em keep finding ways to keep 'em running. I know a guy who ran a Stude on the salt flats,and he ran a 392 in the car and another in the '64 Dodge 700 car hauler (as a spare in case he hurt the one in the racer on the Salt Flats). The car ran 267.??? pretty consistently,but this was back in '80 or so. His race block had been welded back together so many times both sides of the block were made of steel plate. It sure was a fast car for the little money he was able to pull together to run each year.

On the Caddy motors,you can use a BOP manual bellhousing with no mods. BTW-you can run a BOPC transmission,GENTLY,on a Chevy engine,or a Chevy trans. on a BOPC motor,if the need arises;the alignment dowels and two bolts will match on any combination,but this strictly a "Getcha home" measure. Flywheels/flex plates,not so lucky,though I've messed with a conversion kit that would allow a standard Chevy 168 tooth flywheel and iron bellhousing (with a T-400 adapter) and 3 bolt starter,to run a Cadillac engine in a truck,but it looks like these guys have a better arrangement. My idea might be stronger on work trucks,trailer pullers and Ton or bigger trucks. I need a Cadillac crankshaft to see if the bolt holes match (I doubt they will) and to make a jig to build a spacer that can fit whatever center hole diameter it has to fit,maybe drilled for a dual pattern if the bolt holes are different. There are so many things hat have to be the same for this to work, If everything fell into place on the Cadillac motor,there's a chance this could also work on Buick,Olds and Pontiac motors.

Speed

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I knew about the BOP bellhousing/converter housing share with Cadillac. The issue is the pilot bearing. It would be good to see how Cad Company pulls this off. I'd not get creative with a flywheel improvisation. A locating ring or lip must clearly secure and center the flywheel to the crankshaft flange. Can't rely on bolts for centering, even with shoulders. They're not an interference fit. Any out-of-center for a flywheel could be lethal...

Moses

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I agree with the center hole needing to be "perfect" sized for it to work;likewise the bolt pattern would have to be right,the offset from the block would have to be right-there's just too many things that have to be "just right" to hope for an easy conversion unless it's to work for one specific engine. Still,could have been pretty cool,if only......Besides,those truck bellhousings are getting hard to find-I only have a couple left.

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Wow, Speed, wonder what the Cadillac precedent was for the pilot hole in the crank? A manual transmission Cadillac of the 472/500 era is non-existent. Maybe this engine saw additional use in out-of-country trucks? More likely it was easier to machine the crank with a pilot bore to center the back end of the crankshaft. If so, nice that they have a useful pilot bearing O.D. for the bore size.

Are you working your way up to a 472 or 500 Cadillac swap into the GMC 350? Take steering gear clearance into account, I'd like to know if this is practical. The SM420 would fit the pilot, what's the input shaft size on your Clark 5-speed? Wonder if the BOP flywheel fits the Cadillac crank flange or whether you're back to Cad Company's billet flywheel...Curious if the $45 pilot bushing is a bearing or bronze bushing, would guess the latter. If so, perhaps the I.D. could be sized to match the Clark input shaft. Advance Adapters has a shelf full of bronze pilot bearings if you know the sizes. They can even size a bushing to fit. Issue here is Oilite material, a necessity for longevity...Also, the bushing material must match the input shaft hardness/design. If sizing is not an obstacle, a caged (greased and shielded/sealed) bearing with the correct I.D. and O.D. could bridge this gap. The I.D. would need to be a somewhat interference fit on both the input nose and into the pilot bore.

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Do you have '55-'59 Chevy V-8 iron truck housings with the rear motor mount flanges? This was the missing link in many engine swaps...

'60-'62 used the right hand release lever for the hydraulic clutch (dual clutch/brake master cylinder). Did that iron housing also have mount pads? Or was the rear mount under the transmission like later applications with the aluminum housing?

Moses

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All my iron bellhousings had the mount pads;I used one with the hydraulic slave cylinder and used a "gutted" brake master cylinder to power it and built a mount for it to connect to the floor pedal, (I also learned you can use a mechanical linkage bell housing with a hydraulic clutch by cutting a piece of 2 inch angle,drilling the holes for the stock slave cylinder and drilling two holes to match the two flywheel shield bolts behind the oil filter,and mounting the slave cylinder on the bracket so it kinda fits around the oil filter. I used that set up for about 9 years,so it's plenty strong. Since then,I found that a complete system from a Datsun or Toyota works better than the home-built master cylinder,unless you're using a Borg & Beck or Long style clutch. (They'll still work okay,but figure on rebuilding the hydraulics a couple of times per year due to the excessive pedal pressure.) On my '57 Jimmie I ended up using an aluminum housing because nobody makes an iron bell housing for the BOPC pattern. I used the newer clutch fork and made a rod for it that had a "J" at the end that fit into the recess where a pushrod would normally fit. (The Chevy/GMC clutch was a pull type;I tried drilling through the recess,but it's hardened metal and my drill bits just shined it up.)

I think I'm down to one bell housing and V-8 flywheel;I was going to V-8 a '52 Chevy dump truck I got,but I've since found more wrong with the truck than I was told of,so I think I'm going to hand it back to the owner.

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Not really-pretty much any of the V-8 four speed trucks from back then would have it;the big deal is that this bell housing will only fit Pontiac motors up to '63. In '64 Pontiac went to the BOPC pattern,BUT in '64 ONLY they used the BOPC pattern AND the bell housing mounted starter. THAT is the Holy Grail part. (Also the flywheel and starter for that combo.) I ended up with a '64 Tri-power 389 which I put into my first '62 Chevy shortbed;I couldn't find a proper bell housing so I used an aluminum later one and had a 3/4" thick aluminum starter mounting plate added to it. Wasn't pleased with the fit,the starter bolts kept loosening,and every time I drove the truck I got another ticket. I ended up selling the engine and installed a built 350 Chevy motor with the iron bell housing,truck flywheel and standard six cylinder hydraulic 11" diaphragm clutch,with the left side slave cylinder mount I described earlier. (I probably should have shortened the line,since it used to go clear to the right side,but I just looped it a couple of turns and tied the loops to the firewall. Laziness rules!) Worked great,made good power,had a nice choppy idle but still made lots of torque from 800 to 5,000 rpm,and just like the rest of my trucks,it got 10 mpg no matter WHAT I did.

Speed

Edited February 25, 2016 by Speedfixed a mis-spelled word.

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I don't know if this is the right place for this,but I'm putting the '54 GMC up for sale. I'd love to keep it,but I need money more than I need the truck now. It's advertised on Craigslist Reno,SLC,Boise,Vegas,Sacramento and Bay area for $4,000.00. I'll knock a few bucks off for members of this Forum. Time is short,so contact me at sk8080hd@yahoo.com-the creditors won't wait.

Speed

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"Are you working your way up to a 472 or 500 Cadillac swap into the GMC 350? The Caddy swap crossed my mind, I think I'll leave it as it is for now though. Take steering gear clearance into account, I'd like to know if this is practical.

The 350 Ser. has a wider frame,but I haven't measured to see how it all shakes out.A friend suggested cutting the column just outside the firewall,adding a u-joint and using a cabover steering box with a longer drag link to make some clearance where it'd normally be tight,but I don't know how seriously he researched it out.

The SM420 would fit the pilot, what's the input shaft size on your Clark 5-speed? The Clark was an option on this truck,so I'm figuring it'd fit the same pilot as the 420 does; If not,it won't take much to get a pilot bushing/bearing that'll work. I can even find a clutch disc that'll work. clutch Wonder if the BOP flywheel fits the Cadillac crank flange or whether you're back to Cad Company's billet flywheel...I'd just use the Cad flywheel as there are so many variables in trying to use a BOP flywheel. Curious if the $45 pilot bushing is a bearing or bronze bushing, would guess the latter. If so, perhaps the I.D. could be sized to match the Clark input shaft. Advance Adapters has a shelf full of bronze pilot bearings if you know the sizes. They can even size a bushing to fit. Issue here is Oilite material, a necessity for longevity...Also, the bushing material must match the input shaft hardness/design. If sizing is not an obstacle, a caged (greased and shielded/sealed) bearing with the correct I.D. and O.D. could bridge this gap. The I.D. would need to be a somewhat interference fit on both the input nose and into the pilot bore.' My experience with a caged bearing in a pilot application id that you can't install an engine with one unless EVERYTHING is PERFECTLY aligned.

BTW,I have to tow that 40 foot semi trailer from White Rock to Last Chance Road,so I unbolted the flatbed and hopefully Tomorrow Ben will lift the bed off the '54 with his forklift. Then I'll drive it up to my house and install the 5th wheel plate (from my '45 Mack-an original articulated 1945 Dayton hitch) and get it ready to work. (I need to fix the stop lights tie some wiring up and maybe run some carb cleaner through it.) I SHOULD get a trailer plug wired in too. I'll do that,and find an RV 7 blade to Commercial plug adapter if I have time. I might as well-it looks like I'll be needing it often. I already got an offer to tow a double wide from a few miles West of Elko to a place out in River Ranch,,two trips,about160 miles total. Even though it'd be fairly good money,I'm gonna pass. I know the guy who's doing this deal,and I see SO many possibilities for disaster. I finally convinced him to get the Title for the '69 Cornbinder 1800 trailer mover he traded into,get the injector pump rebuilt,throw a used set of rear tires on it that still have tread and just move it himself. Then he won't have to hire a truck and driver. (He has a CDL,all he has to do is get his endorsement for oversize loads.)

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No-I didn't get a lot of response to selling the GMC,so I'm keeping it. Sadly,it looks like the Cummins conversion isn't in the stars,unless a kind soul donates a donor truck. I'm okay with the ol' 302 anyway-it'd work fine for me if I throw a ring-n-bearing job on it and convert it to HEI and a Holley 2 barrel carb. (I DID think VERY briefly of swapping in a 500 Caddy...) I've had the flatbed off it and have been using the 5th wheel to move trailers for friends,but I plan to set the bed back on it in a week or two. I'm going to set it back about 6 inches from the cab,to make room for a proper set of stacks. (single Flowmaster muffler with 4" in and out under the cab,into a "Y",and a foot of flex pipe into each stack,then about 16 inches above the cab,4 inch diameter.Not sure about the mounts but I want 'em attached to the cab,just outside the ends of the rear glass. That way I can keep the stacks even without the flatbed. (That's also the reason for the flex pipe-so cab twisting on the mounts won't rip holes in the back of the cab.

Still working on an air system for it-I figured out a v-belt pulley to fit the crank that will work with an A/C compressor I have prepped to use. (Crank pulley off a 60's Chevy smallblock,held on with the GMC balancer bolt and locked from spinning loose by drilling and threading 3 holes in the balancer and bolting it on.) I still have a 270 block I can use to mock up brackets etc. without having to hang upside down in the engine compartment I'll set the compressor up just like I did on the BroncWorth but with bigger air tank capacity. Not exactly sure how to plumb it clean enough to satisfy the DOT,but I plan to install a pair of glad hands on the back of the cab and some back by the hitch,to make it so I can operate air trailer brakes with a lever on the column. Since I'll only need 'em for emergencies I'd rather not get into the connection from hydraulic brakes to Air trailer brakes. (K.I.S.S. concept) I'm not going to use the truck for Commercial hauling or towing,just to move my own stuff around,so maybe they won't be so strict.

BTW-I have the BroncWorth up for sale,if you know anyone who might be interested. It's posted on Craigslist-Elko and Ruby Want Ads. The sale of it will be financing my membership here and my other two projects.

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Looking forward to your Subscriber Member status, Speed, you'll be able to continue posting topics and replies...

As for the Jimmy and an air brake system, I'm guessing you'll use a York compressor with a crankcase oiling system? That way you have pure air and good volume. Enough? You'll need to verify the CFM of the York compressor, and pulley size will govern output at a given engine rpm. These units were used on AMC/Jeep FSJs, Lincoln/big Ford, I-H and many others with enough sense to value the design. The York compressor is robust and able to handle air tools, many 4x4 trailer runners have gone down that route. Good news is that the truck has hydraulic brakes, right? If so, a dual master cylinder with the correct piston/bore size would be helpful for safety sake.

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Funny you mention the truck's brakes. I already switched it to a dual reservoir master cylinder (from a '79 Chevy one ton van-same 2" bore as stock);there's room for a booster,but it works so well without the booster I haven't seen a need for it yet. I DID use an aftermarket adjustable proportioning valve,bolted inside the right frame rail behind the running board. Took a while to get my front/rear bias tuned in,but I'm happy with it now. (Even pulling the semi trailer from Whiterock to Last Chance Rd, it stopped fine.)

I used to have a V-twin A/C compressor,but couldn't find it when last I looked for it. That York-is it a solid looking upright single piston,looks to be aluminum? My plan is to use the GM compressor I've already prepped,and plumb enough air tank capacity to make up for the smaller compressor. (It'll make more than enough pressure and except for an extreme case will provide fast enough recovery to do what I need. Of course,the DOT may see it differently.

How much is the Membership fee? Any plans to offer stickers,hats,T-shirts,etc. in the future?

Hey-while I have your attention,do you know anyone who has a running smallblock Chevy or a Chevy 292 they might trade for an '85 or so 302 Ford engine? It was a good runner when the guy I got it from pulled it,but he decided to go for a 429 for his truck and closed this one up and stored it in his garage. I used the 2 barrel carb,but other than that it's complete,with a starter,alternator, flywheel and clutch. I need either a small block or a 292 six to put in my '74 Chevy one ton duallie,while I pull the 355 apart and fix a couple of problems. (a broken piston ring and a crank that was improperly prepped. The machinist ,as near as I can tell,machined the rods and mains to .010 under,THEN polished a few more thousandths off it,so when it's cold,with fresh 15/40 in it,it gets around 60 pounds of oil pressure,but once warmed up to running temperature,the oil pressre's only around 35 pounds,a couple of times,under load it dropped to 20,and that's with the high volume oil pump. It doesn't make any noises and it'd probably hold up,but I like to see a little more pressure than that. I plan to keep the crank and just put a good stock iron crank and bearings in it,and worry about the steel crank later. But that's about a $400.00 venture,so it'll have to wait. In the meantime I need it to run reliably enough to handle an occasional highway trip,so I can get my Toyota/Jeep project accomplished.

Speed

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Speed...The G.M. compressor will work if it has its own internal lubrication system. If the compressor requires refrigerant with oil to lubricate, you'll seize the compressor if running pure air through it. The beauty of an upright York compressor is its very own crankcase and crankshaft lubrication system. With crankcase oil at the right level and no seal leaks, these units will operate on their own and pump just air. Look online at the conversion kits and air systems for off-road 4x4s that use the York compressor. It's a proven air supply approach when plumbed properly.

Membership is $12 per year (365 days) and can be thought of as $1 a month or the cost of one quality oil filter. Single pay of $12 carries the subscriber for a full year forward from the date of subscribing...Haven't considered other products, that would be retail product sales, a whole different process with tax charges and such. Nevada still sees electronically/digitally streamed internet information as non-tangible. T-shirts are tangible/physical products. We'll see how the subscriber support goes, if there's enough volume and a demand for mugs and T-shirts, we'll consider expanding.

Understand the engine dilemma...Try a classified ad here at the magazine, emphasizing what you WANT. You're likely better off getting an engine locally at Elko, as freight is spendy for complete engines. You're looking for a common engine.

Moses

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The compressor on the BroncWorth is the stock A/C compressor,drained and re-filled with 4 oz. 10W synthetic oil;it's been working fine for over 5 years of relatively continuous duty. This compressor I have for the Jimmy is different,but is done the same way;I still need to modify the inlet/outlet lines to work-easy stuff,and make the mounting bracket to hang it on the right side of the 302,which I'll mock up on my old 270 block.

The reason I thought of you on the engine is that I have friends headed that way next time Pick&Pull has a half price day,so they could do a deliver and pick up for me. I also thought you might know somebody who may be interested in a trade. If they don't want a Ford motor,what do they want? I might still be able to work something up. Up here,small blocks are of 2 varieties-Expensive and basket case. Big sixes rarely show up at all. I guess a 250 six would be okay too. They WERE available in the one tons too.

Speed

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Speed...We have our fellow forum member 60Bubba making a run through Colorado to pick up a 302 he just snagged for $250. There is a distinct market for the 302s, his find is an MPI with the wiring harness (1994 Bronco donor).

Pick & Pull makes sense on the east end of Sparks. Also, there's one at Mound House near Carson City...Understand that you're likely to find junk on these higher mileage engines. Good luck, hard to find anything "original" in that vintage.

Moses

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Dutch tells me the P&P in Carson/Moundhouse is a LOT nicer to deal with than the Sparks one. I don't know if I'd buy an engine from 'em though-the price isn't bad but it concerns me they won't let me hear it run before I buy. Also to be considered is the young punks who wander through the yard destroying things "just for fun";I caught one throwing dirt down the intake of a relatively new looking 454 last summer. I told the manager about it and identified the kid as he walked by,but the manager didn't seem inclined to detain him.

The 302 I have is an older one,still carbureted,not much electronic but the ignition. no carb on it,I had to trade it for a Holley 500 (?) 2 barrel to put on the BroncWorth (once I get the jets,squirters and power valve matched to a 2.8. Don't know if there's other parts I have to match to the smaller engine or not. Seems weird to me that they use the same throttle bores for my 2.8 as they use for the 390 it came from.

Dutch says he had a couple of V-8's since forever,but traded a 350 for a transfer case for his kids truck and sold a 305 about a week before I asked.

I know where there's a Buick 455 I could acquire,but I have no flywheel or bellhousing. Well-I MIGHT have a bellhousing,I'll have to go look. (Then there's exhaust,radiator hoses,moving the starter wiring to the other side,etc.) It's ironic that my truck ran fine for a couple of weeks,so I insured and registered it and drove it for just about one day before it melted the guts out of the distributor. I built another distributor and it ran fine for two days,then,outta the blue,it started running like crap,WAY too rich.as near as I can tell. (Sounds like a Top Fueler until about 4000 rpm,where it starts to clean up and sounds ALMOST livable by MY redline of 4500.) Since then I've fought that thing for two months. I second guessed myself and gave it an OFFICIAL ignition tune up-cap,rotor,wires,plugs,but while it starts a lot easier,it still runs terrible. What told me it HAD to be a fuel problem was that I'd run 5 gallons of gas through it trying to sort it out,and it suddenly ran GREAT-for about 10 seconds,then ran out of gas. Dutch says,"dump about a quarter can of Seafoam in the tank,top it with another 5 gallons of gas and run it to empty again,or until it runs good again,then if you can afford it,do the same again. I figure that's cheaper and easier than a carb rebuild. I do have a kit for it,if THIS doesn't fix it. If my semi trailer or the BroncWorth sells,I'll GLADLY buy a new carb-I've NEVER owned a new,still in the box carb.

Speed

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Speed...I happen to be a Buick guy, we bought our boattail '72 Riviera when it was a dozen years old, and I really liked the engine. Easy to work with, gobs of torque, that one was a lower compression victim but still ran strongly and got 19-20 mpg on the open road despite the car's weight. I've always had a penchant for Buicks, they were in the family, my folks bought a new GS400 (Special body) in 1967, the earliest car I can recall was the family's 1941 Buick in 1952 when I was 3-years-old. In our years restoring classic car powertrains and steering gears, I built several Dynaflow transmissions, one customer had a '53 Skylark convertible (a Triple Crown car)...Anyway, I never rule out a Buick V-8, and the bellhousing you would need is the BOP pattern.

Your carburetor issue sounds extreme. Cross fingers you will get that new carburetor!

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Do you,by chance,have a Buick 455 flywheel lying around the shop? I believe I have,or have access to,pretty much everything else I'd need to put it in my truck.

Glad you have some interchange resources-that'd help me a lot. I priced a bell housing and flywheel last night,and for new parts on ebay I'm looking at close to $500.00 just for those two components. Add another $125.00 if my clutch is too thin to re-use. (It's developed a very minor chatter lately,not bad enough that I couldn't use it for a couple of years,but ?????)

Edited February 1, 2018 by Speedadding information,also no "Reply" button

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Sorry, but no, Speed. Check the interchange, should be same as later Olds and Pontiac. If so, Pontiacs had higher numbers of manual transmissions. If you need interchange details, let me know...I can furnish.

The 455 Buick V-8 should be of late '60s to 1975/76 vintage. Casting numbers can break this down.

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Okay-the Buick,Olds and Pontiac use the same bell housing,but the flywheels won't interchange. Different spacing from the block,different diameter,different number of ring gear teeth.

In other news,I rented my spare room today,so I have enough to pay some bills and have a little left. Paid my bike insurance,paid off my Dr. bill,went to DMV and had the Chevy one ton's plates transferred back to the '54 GMC.

I decided to put "Mad Max" (the '74 Chevy one ton) on hold for now;I'll eventually find a solution to the problem. I might just pull the motor and fix its internal problems,set it back in and save up for a new Holley carb.

I'm going to Ben's tomorrow (today) to put a battery and some gas in the '54 and get it running,drive it up onto the flat ground and get the bed put back on it. I'm considering installing 2 of the clamps and using my 4 inch ratchet straps to hold it on so I can take it home to properly finish the install. I'll need to build some spacers,drill about 4 more straps and cut 8 more sticks of 3/4" all thread to anchor it better.(That'll make 5 anchors per side.) There's a couple of other things I want to get done on it;make the gas gauge work again,bigger alternator,maybe a new heater motor,if I can't make it sound good by greasing the bushings,and work up a radio and speaker for it. Down the line,there's re-tubing the rear section of the drive shaft,swapping a pair of black leather Jeep Cherokee bucket seats in, and a set of 5 inch exhaust stacks.

On the subject of an air compressor,I think I solved the pulley problem-I might have mentioned this,but the crank pulley off an early 283 V-8 Fits right onto the harmonic balancer and self centers-all I need to do is drill and tap 2 or 3 holes in the balancer hub to anchor it from spinning loose . The crank bolt,with the help of a 3/16" spacer between the pulley and the balancer,holds it tight,but there's a pretty huge pull on it under load. Maybe 6 bolts. I don't think it spins fast enough to be at risk of throwing itself apart or anything. I still need to engineer a bracket on the right side of the engine and decide whether to use an idler for belt tension or just make the bracket pivot. I like the idler idea better.

Hey,what do you know about Perkins Diesels? A friend says he has a line on a six cylinder Perkins Diesel engine out of a forklift I could probably get for $1700.00 if I can wave some cash under his nose. Its bell housing is already drilled for a GM truck 4 speed. I'll try to get more info on the engine now that I can buy some gas.

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Speed...First off, I know you're on a tight budget, thanks much for moving from a Member to Subscriber Member, we value your participation at the Forums!

Understand the flywheel issue on the BOP engines. These were independent GM Division engines prior to 1977. Yes, there was a time when Buick, Oldsmobile and Pontiac had their own design and engineering status. Some of us remember that far back. Prior to mid-'sixties, these engine divisions were even more autonomous, and parts interchange was even less likely.

Good angle on the balancer/pulley for the air compressor. Apparently this will work? Glad you recognize the pulley load factor for the air compressor. Sounds like the 283 pulley was for a factory air conditioner/power steering engine? If so, that would be designed for a considerable load. Be careful and use good judgment here...

Perkins engines are/were British and have been around for a very long time. Jeep optioned a tiny 4-cylinder type, a smoke-belching, CJ-era option. Perkins is a very common marine engine, and there is a dealership and parts network in the U.S. My writing colleague Jim Allen talks about the Jeep CJ engine application at this Four-Wheeler link: http://www.fourwheeler.com/features/1404-1966-jeep-cj-5-perkins-diesel-encyclopedia/. Here's a quote from Jim:

"The Perkins 4.192 made 192 cubic inches from a 3.5-inch bore and a 5-inch stroke. It cranked out 62hp at 3,000 rpm but 143 lb-ft of torque at 1,350 rpm. It was one of Perkins’ old-school, three-main-bearing, direct-injected engines that was in production from ’58 into ’72. It was seen in the Massey-Fergusson 65 tractor and in stationary and marine applications worldwide."

Old school for sure with 3-main bearings, and what a stroke length! I'm not a fan...That was an earlier engine, not clear where Perkins engineering has gone since. Check out Perkins engines online or at Wikipedia...What vehicle would get this forklift engine?

Moses

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If the Perkins six makes enough torque and power I'm looking at it for the '54. If not,maybe it'd be workable in Max. I'm trying to find more info on this particular engine,i.e. engine model number,ID number,etc. so I can look up some spec's on it. The guy who knows the guy who has the engine is a little hard to reach lately.

The '54 runs again and is ready to roll,so as soon as I can arrange a ride I'll go get it. If the yota had the bumper/grille guard/push bar I want on it ,I could just put the tow bar on it,drive IT out there and tow it home behind the '54.

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I've made a shortcut to that link,but I still don't know any numbers or specific ID on the engine yet. I'm trying to get Pat to tell me where the engine is so I can go do some detective work. Pat says it was in a forklift that was in a fire on the docks in San Francisco,but the engine wasn't touched. I noticed on the Perkins website the power and torque are referenced in a different terminology than we use,so I'll have to find a "conversion chart" to see what I'm dealing with.

On this Eaton 1350 2 speed axle,is there any reason I can't work up an electric shift for it instead of the vacuum set up? I'd considered a solenoid,but it wouldn't stay shifted without overheating,so I guess I have to figure out a way to adapt the electric shift to a vacuum axle.

Speed

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Speed...The later Eaton differential lockers are electrically actuated. Though internal shift clutches, there might be a way to go with an Eaton electric/magnetic solenoid approach. Here is some fodder to ponder:

Also, Tremec heavy-duty truck gearboxes use mechanical linkage and also pneumatic shift mechanisms...An air actuated system (pressurized) might be an alternative. There are many hydraulic controls and air pressure controls that feature a cylinder with a control valve (cab mounted in your case).

An even simpler, less involved approach might be a cable/manually activated or mechanical shift rod linkage with brackets that would serve the same function as the vacuum diaphragm. The issue with a manual control (possible prototype is the Spicer or Brownie auxiliary two-speed transmission/gearbox shifters) would be kickback and assuring that the axle holds in gear and remains engaged. For the Spicer/Brownie, there would be internal shift rod detents and other means for keeping the box in gear. We'd have to look at your Eaton 1350 internals to see whether there are built-in detents to keep the gears engaged.

If not, a trip-over handle mechanism might suffice, each end of the lever's positions capable of "locking" the cable or shift rod in a fixed position until you shift again. In any case, you do not want the two-speed axle mechanism to kick out of gear by itself at the wrong time—like on a downgrade when you need compression braking!

Moses

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As I understand it,a spring makes it default to Low range if vacuum fails,but the vacuum holds it into High,unless the vacuum in the tank is depleted by a leak or a LOOOOONNNNG up hill grade,where it either downshifts or creates a neutral/grenade situation. Maybe removing the spring and making a "ball and spring" detent for each end of the lever would hold it into which ever speed one chooses,and a solenoid would only have to be momentary to push the lever from one gear to the other. I'd REALLY prefer some form of electric shift,they're much easier to use while shifting the transmission.

I know where there's an electric Eaton 1350 in Carlin;I've been working on a deal with the owner for the whole truck,a '57 GMC 350 with a post hole auger and the engine froze up,but maybe he'd consider trading the punkin for my vac. shift one,since it's unlikely he'll ever put it on the rod again anyway. (I'll need the speedometer too,so the speedometer can correct from low to high and back.)

Speed

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Speed...In considering why they did not use a mechanical (i.e., shift rods like a Brownie or Spicer auxiliary transmission) system for two-speed axle engagement, the answer is simple: The axle moves up-and-down independent of the frame. Vacuum, electric, hydraulic, flexing cable (like E-brake cables), or pneumatic systems allow for a flexible shift control that complies with the axle's movement over its range of travel.

Look at the '57 GMC 350* electric mechanism, it may be nothing more than an adaptation on your vacuum setup. Maybe the shift mechanism parts will interchange with your vacuum setup and allow you to keep your axle center section? Take a peek and compare parts closely. As for climbing grades with a vacuum shift system, yikes! I'd want a vacuum reservoir tank on that circuit...

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Maybe the shift mechanism parts will interchange with your vacuum setup and allow you to keep your axle center section?

I'll check into that-I don't know if I have the books for it,but I may be able to find out if there's a different carrier listed for electric and vacuum or if they both show the same part number.

BTW-I talked to the guy with the auger truck,and he says he'd rather sell (or trade) the whole truck than just the parts,so now we just need to reach an agreement on price or what he's currently looking for. As I understand it,this truck was in use until it blew a hydraulic line,after which they "retired" it and bought a newer one,so there's a possibility I could get it to run well enough to drive it home.

More news-I got the speedometer cable adapter I believe will give me a speedometer on the '54 again. I've been sick for the last 9 days,but as soon as I'm up to it I'll go out and see if the adapter fits. (It has a Ford part number and was listed for Ford trucks from the 60's-70's.)

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Speed...Good sleuthing approach for the shifter and carrier fit. The auger truck sounds interesting. We're both keen on 'fifties GMC trucks. That one should have a 347 Pontiac V-8 or a GMC 248 or 270 four-main bearing inline six. 1955-59 GMCs use 287/288, 316/317, 336 or 370 GMC versions of Pontiac V-8 engines. All Smokey Yunick* territory...Cool!

*Smokey Yunick had a strong influence on my interest in Pontiac V-8 engines. In the 'sixties, I was a real fan...Here's his bio: https://en.wikipedia.org/wiki/Smokey_Yunick. In 1968, I transplanted a 347 Pontiac V-8 with dual-coupling Hydramatic into my '55 Ford F100 pickup at a time when everyone else was obsessed with Chevrolet and Ford engines.

The speedometer cable adapters for that era are typically Stewart-Warner and will fit a variety of applications. Good if that includes Ford to GMC.

Sorry to hear you've been under the weather. We have a five-year-old grandson and go to Discovery Museum at Reno a lot. Wife Donna calls the facility a Petri dish for Reno/Sparks children's bugs. We finally caught one. I'm stubborn and have kept working anyway, we're wearing the head/sinus cold out. A war of attrition! Better than the flu, right?

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Amen to that! Typically,I'll get mostly over this but the cough will keep beating on me for a couple of weeks.

This auger truck has the 270 inliner in it,missing some small parts,but like I said,I think I can come up with enough to make it a runner. A minor concern is that if I DO make a deal for it,I have no place to park it. Well-that may not be entirely true if I make the deal quickly enough. My friend Ben,who has let me store my vehicles on his land,has mentioned building a fair sized chain link fence around his acreage,and I bet an auger truck would work well for him if I fix the hydraulics and find a smaller bit for it someplace. (Maybe if I check where the current owner bought the truck they still have the accessories for it.)

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It LOOKS to be in decent shape,so I don't think it has a lot of miles on it. not banged up,usual issues aside from the engine-brakes,tires,glass seals,little rust,etc. Since it was used only for setting power poles in town,I'd be surprised if it has 100K on it.

UPDATE-06-06-2018

My '54 GMC is likely to get only a little upgrading;.I have an OEM radio for it I need to have rebuilt,if I can find anyone who can do it. I'm also needing to replace the rear section of my drive shaft as its yoke is worn out. I SHOULD replace the clutch,but probably will wait until it gets enough chatter to shake the mirrors out of adjustment. The engine could stand a rings-n-bearings job,but that'll have to wait until I have some money to invest. I'm going to revisit using the truck to haul scrap metal to the scrap recyclers in Southern Idaho and Northern Utah,since Pacific Steel is paying considerably less than anywhere else I could go. I figure my 2 Ton can haul enough to make the trip profitable for me.

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There is not a lot of altitude change until I-84 over to Boise,where its actually lower than Elko. What I was hearing is that most of Southern Idaho is around 4,000 feet,Elko is 5,100,and there's several summits of about 55-5800 feet. Not sure yet what route will get me to Idaho Falls w/o any weigh stations. I DO know how to bypass the Elko one. Higher altitude won't bother me with this truck-I have enough gearing at my disposal to climb whatever's in front of me. Right now,the truck's needs are a fresh alternator and 5/8" belt (to replace the 7/8" belt-you can't find pulleys to work with a 7/8 belt!) I also want to install some LED bed marker lights,but those aren't as critical.

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The heater on this truck actually works pretty good;it's noisy but functional. (I think it's still the 6 volt motor;a 12 volt replacement isn't too expensive.) I need to build some defroster hoses-the originals just crumble when I try to do anything with 'em. I know I can buy a set for under 20 bucks-they're just such a pain to route so nothing interferes with their fit. (Wipers linkage in particular.)

Hey,I still have that 12 volt radio that fits my truck-actually I have one from a '60 GMC LCF,one from a '53 or so Chevy truck and another one for parts, I can't remember what it was in;I'm looking for someone who can/will build me a good,reliable radio for my truck. I like the tube type radio-it pulls a LOT stronger signal reception than the transistorized junk they sell now. The GMC one is complete except the tubes are missing and the dial lens needs to be replaced. I think LMC sells that-I don't know what tubes it takes or where they go. I'd like to get that done and find an FM converter for it,the old school one that fits under the dash. I think LMC also sells the chrome speaker box that mounts above the windshield and they have an upgraded speaker that fits it. I figure once I swap the Clark 5 speed for a good SM420 and build a decent exhaust (3" pipe,Summit Racing Flowmaster knock-off w/3" in and out,short piece of flex pipe after a 90 degree,feeding into a 3" stack that extends about 18" above the top of the cab,with a straight cut end and a rain-cap,assembled with band type clamps,I'll even be able to hear it. I doubt I'll be using the 5th wheel plate anymore on this truck,so I'll attach the stack to the headache rack on the flatbed. (That reminds me-I need to move the bed forward on the frame about 4 more inches to center it over the rear wheels. I don't think I'll need that much room for the stack's clearance.) I also found a deal on H-4 Halogen headlights for this truck and have some 85/100W bulbs to install in 'em. It'll be SO NICE to be able to see what's down the road far enough ahead I don't have to worry about surprise obstructions!

Speed

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Speed...The vintage 12V radios always needed an "OZ4" tube. Why? Who knows...In the 'sixties heyday of the 'Tri-Five' Chevy, we checked tubes at the drug store and local Western Auto where they sold radio tubes...

The Clark 5-speed brings back memories. I shepherded a flock of vintage light and medium duty trucks in the late 'sixties/'early 'seventies that included an I-H dump truck with the Clark 5-speed transmission and RD406 (massive inline six) gas engine. Sure you want to give the Clark up for an SM420 four-speed? Tired of double-clutching?

Moses

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" Sure you want to give the Clark up for an SM420 four-speed? Tired of double-clutching? "

I don't mind double clutching-actually I "half-double clutch",half the work. As I reach the "float" part of a shift,I just slide it into neutral and let off the gas,then as the rpms come down close to idle on an up shift I hit the clutch and shift into the next gear;on a down shift,I lift the throttle and pull it into neutral,jazz the throttle a bit and shift to my next lower gear. I actually LIKE the weird shift pattern-it kinda amazes passengers,who think it'll have its gears on the same pattern their half ton GMC does. The main thing is that I like the feel of the 420,it shifts easier and is a LOT quieter going down the road. Being mostly synchronized isn't a bad thing either. Without looking up the individual gear ratios,it feels like its ratios are close to the same as the first four speeds of the Clark,but I really can't use the Overdrive on the Clark anyway,unless I can grow another hundred or so horsepower. The Clarks 5th gear is a .85,and the Brownie I have is a .74 Over;I don't have the power,even EMPTY,to run both overdrives,so if I have to give one up,going to a 420 main box will give me virtually all the gears I have now except one overdrive. Only downside I see is I'll have to have BOTH drivelines modified,but if it's gonna be on the highway at all that's probably a good idea anyway. Plus,if I get a 420 from a one ton or bigger truck it'll have my beloved transmission mounted E-brake!!!

I have a grocery bag of tubes and when I still had a list of what tubes the GMC radio needed I went through 'em,but there were no matches. I'll trade 'em for a set of the right tubes for my radio. (BTW-Elko High School's Electronics Class has my tube tester,they'll probably check any tubes you have for free.) Hey,I discovered Summit Racing sells H-4 Halogen headlights in a 7" round. They're around $56.00 a pair,and I can get 85/100W bulbs for 'em for a couple of bucks each.You want some REAL light to drive by for your older car or truck-this'll do the job!

Speed

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All sounds good! They must have used the Clark without a Brownie as well, since as you share, it's all the overdrive the truck can handle...The SM420 is stout if your axle gearing is low enough to apply reasonable torque loads to the transmission. SM420s were abundant over the years, used from postwar through the mid-'sixties, should be plenty of them available near Elko. I'm guessing the Clark has a higher torque rating, though they didn't advertise transmissions that way when your Jimmy was built. Clark transmissions usually appear in working trucks like dumps and mixers, true medium duty workhorses.

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This truck had a 270 and a 420 originally,but probably had the Brownie installed before the current 302/Clark,which was pretty much standard issue for the Military trucks of larger than Deuce and a half sizes. The Clark doesn't have an E brake. Since I have other work to do on this truck (slide the bed forward,bigger alternator,dual batteries,100W headlights,new clutch,re-tube drivelines and change the front yoke,build a proper exhaust system),if you know anyone who has a one ton up 420 with the trans. E-brake who wants to trade it straight across for an overdrive,I'll pull the Clark out for 'em. I don't want to trade for a worn out 420 though,it needs to be in at least fair,usable shape. I suspect the Clark may need an output shaft bearing,but it works fine otherwise and is quiet,for a crashbox.

Speed

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The 270 inline six was a great engine, obviously the 302 has notoriety. My late friend Jack Clifford had many drag racing experiences around the 270/302. All of the GMC sixes were better than the pre-'54 Chevrolet Stovebolts. GMC offered a full-pressure lube system with insert bearings instead of poured rods (shimmed) and dip-and-splash rod lube.

Anyway, I'm obviously a 228-248-270-302 fan, their only weakness as such was the four-main bearing crankshaft. Later (1963-up) 230-250-292 seven-main bearing engines are arguably tougher. One solution: Don't spin the hell out of a 4-main bearing engine!

Finding an SM420 without wear might be a challenge, the last use of this transmission was 1967, phased out by the stout SM465. (The early SM420 boasts a 7.05:1 compound low gear, a major advantage, the SM465 is stronger by design.) E-brake on the transmission (medium duty truck) would imply hard work. It's not that difficult or costly to freshen up an SM420 with at least a bearing and small parts kit plus brass synchro rings...If you find an SM420 with E-brake and good gears, a light rebuild would be advisable.

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The MAIN reason I've always liked the 420 is the "deep as an oil well" low gear. Was there ever a 435 or 465 with anything close to the 420's low gear? Were either of 'em offered with the E-brake option(?)?

Regarding the limitations of the Jimmie Six,I've NEVER been a fan of high revs. When I had my 80 Harley 80 incher,I had 'er geared to run 80 mph at around 2500 revs. IT was happy there,I was happy there,it was perfect,and with solid lifters and a points ignition it had plenty of torque to get rolling even riding two-up with a load of yard sale treasure.

BTW-the 4 main six seems to be VERY critical of balance,so when a build is done you have to have the rotating assembly balanced REALLY well. Another thing that will make it live longer is a set of lighter pistons-those stockers would be a liability if it's gonna wind more than 3500. (Not sure how a set of light,higher compression pistons would hold up in a 2 ton truck,though-I'd assume lugging it down to 300 rpm would no longer be an option.) I'd be curious -to see what changes happen with pistons 1/3 the weight of stock ones,with a couple of points higher compression-horsepower curve,torque curve,MORE torque or less,MORE horsepower,or less? At what rpm?

I've set my own redline for the 302 at around 2750 if needed,but usually around 2600 against the factory's 3400. Besides,a Jimmie doesn't NEED more than 2600 to do its work-twisting it beyond that's just bangin' your head against the wall.

It looks like finding the 4 speed I'd like will be a long shot,so I'll roll with the Clark for now.

My next projects have to be a new alternator,and 5/8" pulley,a new 5/8" belt,rebuilding the rear section of drive line,better headlights,swapping the Cherokee black leather bucket seats in,and a new clutch. (MAYBE new rear axle seals and brakes...) And an EXHAUST system. I've decided on a high flow quiet muffler in 3",going back into a 3" stack on the left. A LOT of this will have to wait until later,as I have other more pressing things to deal with. The alternator/belt/pulley is a MUST HAVE.

Speed

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Speed...The SM465 has a compound low of 6.55:1; the NP435L and NP435E versions have the sought after compound low of 6.68:1; the sought after SM420 has a 7.05:1 compound low gear. There are taller geared versions of the NP435 and SM420. I believe all SM465 units are 6.55:1 in 1st gear. Always check the 1st gear ratio before buying any of these units.

The NP435 dates to 1962, so there are applications with an E-brake on the output end. 'Sixties and even later medium duty truck applications of the NP435 and SM465 should turn up an E-brake at the output. Here is a nice rundown of the NP435 applications. I-H and GM medium-duty models would be a place to start:

The Clark transmission is a good default position. They were found in trucks similar to yours and work well for their intended usage. I serviced and drove that early 'fifties I-H medium duty with the RD406 inline six and Clark 5-speed. It worked perfectly fine and kept my double-clutching skills sharp.

Higher compression with a long stroke vintage engine design has always been dicey. Running a maximum of 8:1, possibly 8.5:1, seems plenty for any of these engines. Your rpm ceiling makes perfect sense, 3000 rpm is well up there, though I'm sure vintage racers reached 4,500-5,000 rpm. For how long? Anyone's guess.

Moses

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The GMC has been upgraded to a dual reservoir master cylinder the same bore size as the original;I eliminated the Hydrovac,but the brakes work well without a booster,and there's room to add one if I need it. I had to use an adjustable proportioning valve which I mounted inside the right frame rail near the battery box,to compensate for the master cylinder's Disc/Drum configuration.

The A/C compressor is for an on-board air system,to inflate tires,run the air horns and possibly operate air brakes if I need to move a trailer so equipped. It wouldn't be DOT legal,but would work for a short distance. I could make a very basic set-up and operate the trailer brakes via a trolley valve on the steering column-I have a couple in the shed.

Speed

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On that dual reservoir master cylinder, the disc brake circuit does not hold residual pressure in the circuit. (Disc brakes do not require residual pressure. Late systems use a very slight amount of residual pressure in the 2 PSI range to align the pads gently against the rotors.) If the front disc brake port does not have a residual valve behind the flare seat, your brake wheel cylinder cups will not stay expanded when the brakes are released.

Normally, with a drum brake master cylinder, the residual valve(s) will hold 10-12 psi in the lines with the pedal released. This is way less pressure than the shoe return spring tension, so the brake shoes retract completely. The pressure is simply to keep the lips of the rubber wheel cylinder cups/rubber seals expanded and sealing against the bores of the wheel cylinders. If there is no residual pressure, the cups will collapse and allow fluid to seep past these cup seals. The symptom is leaking wheel cylinders.

Presumably, you have the disc circuit feeding your front brakes? See whether you have leaks at the front wheel cylinders. There is an add-on residual valve kit available from Wilwood: Wilwood 260-13784 Red 10 PSI Residual Pressure Valve with Fittings. Note the 10 PSI details:

This kit enables adding a residual valve at a fluid line rather than fiddling with the master cylinder's port flare seat. You'll get the idea when you see the valves. There is also a 2 PSI valve available, but this is for a disc brake circuit. Modern disc brake systems do use a very low amount of residual pressure to keep pads closer to the rotor.

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So far no problems other than having to pump up some pedal if I leave it parked for 6 months or so. I'll get one of those valves in the front brake line when I bring the truck home to replace the alternator and add the high power headlights. I'm also going to slide the flatbed about 6 inches closer to the cab and re-attach it. Last time I put it on I left it back a ways because I planned to add dual 4" stacks to it,mounted to a cross-frame bracket between the cab and the bed,but now I think mounting stacks to the headache rack would work fine;and if I decide to remove the bed and install the 5th wheel plate again I can use that time to build the bracket and bolt it to the frame,with nothing in the way. If I do it right,it,and the pipes,will fit with the bed in its original location.

Speed

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This would explain the pedal pumping after setting. Another advantage with the residual valve will be protection against air/moisture absorption into the wheel cylinders when parked. The cups are not sealing snugly, which allows air seepage into the cylinders. This leads to corrosion in the wheel cylinder. Brake fluid is hygroscopic.

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Looking back,with all the gearing this truck already has,I guess it doesn't matter how low first gear is,so that makes the transmission search a lot easier. I'd STILL like to find the transmission mounted E-brake though,but NOT to use on the main box. I just want to use the lever and ratchet assembly,and I'll build a rod long enough to reach from the stock E-brake lever to the brake on the back of the Brownie,to replace the cable operated "on or off" lever in the cab.

I'm starting to think,AGAIN,about working this truck;Scrap metal is so low here it doesn't even pay enough to buy the gas it takes to haul a car to the scrap yard in Osino,so I'm looking into maybe hauling 3 or 4 cars at a time up to Idaho Falls,to the salvage plant there-IF the price is high enough to be worth the trip. If I'm getting good info,as long as I'm not hauling FOR someone,I'm just transporting my OWN metal,for MYSELF,so the DOT shouldn't bother me,as long as I don't go over the 26,000 weight limit or overload my truck's safe load limit. (According to my figures I'd have a very generous 18,000 before I'm anywhere close to 26,000.) I know I'd probably eventually end up having to scale it for those reasons,and I expect they'd be doing safety inspections,just because of the age of the truck. I think I can go North to Mountain Home,cross I-84 and there's a side road up to Idaho Falls that doesn't have a scale house,but I need to ride the bike up there and verify my information.